Image Formation Lab

Parallel lines, points at infinity and a vanishing point

from a top-down view (affine) to a camera looking along the road (projective)

Drag the four corners: which transformation can produce the shape?

map pixels forward instead of backward

A pinhole camera: x̃ = K [R | t] X̃

The image, 640 × 480 pixels. The highlighted corner is followed step by step on the right.

Top view: world x to the right, y forward, z up.

focal length f (pixels)

principal point c_x

yaw (turn right)

pitch (look down)

camera x

camera y (distance back)

camera height z

Field of view → focal length in pixels: which field of view?

field of view from the data sheet

Two views: when does one image map onto the other?

rotation of camera 2 (yaw)

baseline: camera 2 moved sideways

near box (depth 4 m)far wall (20 m)○ predicted from image 1

Lens distortion: straight lines that are not straight

k₁ (radial)

k₂ (radial, r⁴)

p₁ (tangential)

p₂ (tangential)